1. Field of the Invention
The present invention relates to an ink ribbon cassette that employs a replaceable ink ribbon, and an apparatus that uses the ink ribbon cassette.
2. Description of the Related Art
FIGS. 16-18 illustrate a conventional ink ribbon cassette for use in an impact printer. Referring to FIGS. 16-18, an ink ribbon 104 is sandwiched between a drive gear 102 and a driven gear 103. The drive gear 102 is driven to rotate in a direction shown by arrow A (FIG. 17), thereby driving the ink ribbon 104 to travel in a direction shown by arrow B (FIG. 17). The drive gear 102 and driven gear 103 may be replaced by a feed roller and an idle roller, respectively.
Referring to FIG. 18, a body 106 and a cover 105 have holes formed therein. The drive gear 102 and driven gear 103 have their shafts that extend through the holes such that the drive gear 102 and driven gear 103 are rotatably supported by the body 106 and cover 105.
The conventional ink ribbon cassette is configured such that the drive gear 102 and the driven 103 remain in meshing with each other and rotate on their shafts mounted to the body 106 to advance the ink ribbon 104. An ink ribbon cassette, however, requires some disassembly and reassembly for removal from and installation to the printer. In addition, the installation of the ink ribbon 104 between the drive gear 102 and driven gear 103 requires precise alignment of the ink ribbon 104 with the drive gear 102 and driven gear 103, which is tedious and tends to be difficult for unskilled personnel.
In addition, the ink ribbon 104 sandwiched between the drive gear 102 and driven gear 103, may be wrinkled to cause an ink-ribbon jam.